When I log into google from google.com, then open gmail, Integrated Gmail 2.5.5 causes the browser to redirect to google calendar.
When I log into google calendar first, then go to gmail, the same thing happens.
When I log into gmail directly, the same thing also happens.

When Integrated Gmail is disabled, I don't get that behavior, but I also don't get reader and calendar in the same window anymore(which is expected behavior, but not the goal).